Endodontic file

Abstract

An endodontic file for a motorized rotary handpiece includes a coupler element for coupling to the handpiece, a central longitudinal flexible core including a central flexible cable supported by the coupler element, and a helical wire surrounding the core and extending toward a tip of the core opposite the handle end. The flexible core includes a first plurality of inner strands twisted together in a first direction and surrounded by a second plurality of outer strands twisted in an opposite direction. The tip of the core is chamfered and unbonded and protrudes beyond the helical wire at the tip whereby in use reversing a direction of rotation of the endodontic file after the tip of the core reaches the apex of the root canal, unwinds the outer strands, which operate as a brush during removal of the endodontic file from the root canal.

Description

FIELD OF THE INVENTION[0001]The present invention relates to endodontic devices.BACKGROUND OF THE INVENTION[0002]Modern endodontic treatment involves removal of the damaged pulp, followed by cleaning and shaping of the root canal space, irrigating, and filling with biocompatible material such as gutta-percha and a root canal sealer.[0003]Shaping of the canal is performed either manually, using a series of stainless steel hand-held files, or mechanically, using rotary nickel-titanium files adapted to fit a standard or dedicated dental handpiece.[0004]The manual process relies on the experience of the dentist, is physically difficult to perform and is time-consuming. The use of files requires repeated changing between numerous different rat-tail files, progressively increasing from the smallest to the largest. Its reach to the apical constriction for widening and removal of the smear layer is limited. The reason for such limitations relates to the moderate elasticity of the steel file...

AI Technical Summary

Benefits of technology

The invention is an endodontic file for a motorized rotary handpiece that can be used to prepare root canals in dentistry. It consists of a coupler element, a flexible core with a helical wire, and a chamfered tip. The file has a small diameter and is designed to expand and clean the root canal while rotating. The file is particularly effective in removing debris and filings. The technical effect of this invention is that it provides a faster and more efficient way for dentists to prepare root canals, using only one or two files.

Problems solved by technology

The manual process relies on the experience of the dentist, is physically difficult to perform and is time-consuming.

Its reach to the apical constriction for widening and removal of the smear layer is limited.

The reason for such limitations relates to the moderate elasticity of the steel files and the risk of fracture when excessive force is applied.

Although the field of elastic rotary nickel-titanium endodontic files has developed greatly over the last few years, fracture (separation) of nickel-titanium rotary files is still often reported, and hence the use of such is restricted.

As a result, the cost of files and the related equipment per endodontic treatment has increased and instruments are typically operated only by experts in the endodontic field, while non-specialists use standard handpieces in a risky procedure.

Additionally the round cross-section of the file prevents adequate cleaning when the canal cross-section is oval or narrow in shape.

In such cases, enlargement of the canal cross-section to accept the round cross-section of the file, may weaken or perforate the wall or the apical portion of the canal.

The same risk of perforation applies in case of a curved root canal, where the file tends to follow the path of least resistance, acting rigorously on the convex walls within the reach of the file, and insufficiently over the concave portions.

The level of skill required by the dentist is high, and the supplies are expensive thus ruling out use of such files for all but a small fraction of practitioners.

Moreover, notwithstanding the improvements to endodontic files contemplated by the above-referenced prior art, shaping of the root canal still requires use of multiple files, resulting in root canal treatment being tedious for the dentist and uncomfortable for the patient.

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